Had Christian doctrine not evolved in response to this challenge, it would have lost credibility as the Kingdom of God failed to show up on Earth–as generations and generations of Christians were seen to have died without getting their reward. So the Kingdom of God had to be relocated from Earth to heaven, where generations of Christians had presumably gotten their reward–and you could, too, if you accepted Christ as your savior.

Noting that Luke’s account did not appear in quite the same way in the other Gospels, Wright speculates that Luke may have borrowed a bit from some of the Pagan religions:

Am I saying that Luke stole his afterlife scenario from a competing religion? Not with great confidence, no. But if you wanted to indict him on this charge, you would not be wholly lacking in evidence. The evidence would focus on the Egyptian God Osiris. Osiris bears a certain resemblance to Jesus as Christians would later come to conceive him; Osiris inhabited the afterworld and judged the recently deceased, granting eternal life to those who believed in him and lived by his code. But Osiris was doing this a long time before Jesus was born, and meanwhile he had migrated to the Roman Empire, where he had developed a following.